Standard Reflow Profile for Standard Lead-Free Packages

Transcription

1 Standard Reflow Profile for Standard Lead-Free Packages Standard Reflow Profile for Standard Lead-Free Packages Document Revision 1.1 December, of 6

2 Table of Contents 1 INTRODUCTION... 3 REVISION HISTORY of 6

3 1 Introduction The objective of this document is to provide Reflow Soldering Temperature Profiles. The reflow here in provided is for reference only. Users are advised to optimize their own board level parameters to get proper reflow outcome. Table 1: Reflow Profiles Profile Feature SN-PB Eutectic Assembly PB-Free Assembly (Preheat/Soak) Temperature Min (T SMIN) 100 C 150 C Temperature Max (T SMAX) 150 C 200 C Time (ts) from (T SMIN to T SMAX) seconds seconds Ramp-up rate (T L to T P) 3 C/second max. 3 C/second max. Liquidous Temperature (T L) 183 C 217 C Time (t L) maintained above T L seconds seconds Peak package body temperature (T P) Time (t P) within 5 C of the specified classification temperature (T C); see Figure 1 and Note 1 For users, T P must not exceed the Classification temp in Table 2. For suppliers, T P must equal or exceed the Classification temp in Table seconds (Note 1) For users, T P must not exceed the Classification temp in Table 3. For suppliers, T P must equal or exceed the Classification temp in Table seconds (Note 1) Ramp-down rate (T P to T L) 6 C/second max. 6 C/second max. Time 25 C to peak 6 minutes max. 8 minutes max. temperature NOTES: 1. Tolerance for peak profile temperature (T P ) is defined as a supplier minimum and a user maximum. 2. All temperatures refer to the centre of the package, measured on the package body surface that is facing up during assembly reflow (e.g., live-bug). If parts are reflowed in other than the normal live-bug assembly reflow orientation (i.e., dead-bug), T P shall be within ± 2 C of the live-bug T P and still meet the T C requirements, otherwise, the profile shall be adjusted to achieve the latter. To accurately measure actual peak package body temperatures, refer to JEP140 for recommended thermocouple use. 3. Reflow profiles in this document are for classification/preconditioning and are not meant to specify board assembly profiles. Actual board assembly profiles should be developed based on specific process needs and board designs and should not exceed the parameters given above. For example, if T C is 260 C and time t P is 30 seconds, this means the following for the supplier and the user. For a supplier: The peak temperature must be at least 260 C. The time above 255 C must be at least 30 seconds. For a user: The peak temperature must not exceed 260 C. The time above 255 C must not exceed 30 seconds. Table 2: SnPb EUTECTIC PROCESS - REFLOW PEAK TEMPERATURES (T C ) PACKAGE THICKNESS < 350 < 2.5 mm 235 C 220 C 2.5 mm 220 C 220 C of 6

4 Table 3: PB-FREE PROCESS - REFLOW PEAK TEMPERATURES (T C ) PACKAGE THICKNESS < > 2000 < 1.6mm 260 C 260 C 260 C 1.6mm-2.5 mm 260 C 250 C 245 C > 2.5mm 250 C 245 C 245 C NOTES: 1. At the discretion of the device manufacturer, but not the board assembler/user, the maximum peak package body temperature (T p ) can exceed the values specified in Table 2 and Table 3. The use of a higher T p does not change the classification temperature (T C ). 2. Package volume excludes external terminals (balls, bumps, lands, leads) and/or non-integral heat sinks. 3. The maximum component temperature reached during reflow depends on package thickness and volume. The use of convection reflow processes reduces the thermal gradients between packages. However, thermal gradients due to differences in thermal mass of SMD packages may still exist. Figure 1: Reflow Profile 4 of 6

5 Revision History Document Issued Rev. No. Date 1.0 Aug Dec, 2017 Section Page Description Edited By Reviewed By Preliminary Danny Ho Patrick Li Update cover page Danny Ho Patrick Li 5 of 6

6 Copyright Notice This specification is copyrighted by Ltd. No part of this specification may be reproduced in any form or means, without the expressed written consent Ltd. Disclaimer Ltd. assumes no responsibility for any errors contained herein. Copyright by Ltd. All Rights Reserved. Ltd. TEL: (852) FAX: (852) of 6